I can only speak for the iOS side. (I understand Android has fewer limitations on what can be done.) Have a look at Pythonista for a full Python environment, o

I can only speak for the iOS side. (I understand Android has fewer limitations on what can be done.) Have a look at Pythonista for a full Python environment, or Coda for a web dev environment. There's also all the web-based tools, hopefully some are optimised for smaller screens. On iPad you have Playgrounds to run all sorts of Swift code. For kids, there's other simple environments in apps like Scratch. So as you might imagine, I disagree with your statement that "'smartphones' nowadays makes it difficult for you to create on them", and think that's just a case of nostalgia on your behalf.